Building element.



S. GROSSMAN.

BUILDING ELEMENT. APPLICATION man JUNE 4. 1917.

1 ,257,2Q1 a Patented Fab i9, 191%,

INVENTC'B Elm r51 @UJWWQYZ BUILDING ELEMENT.

Specification of Letters Patent.

- SAMUEIZ GROSSMAN, or NEW YORK, N; Y.

Patented Feb. 19, 1918.

Ajiplicatioafiled m 4, 1917. Serial No. 172,698.

To all whom it mag concern:

Be'it kfiOWHllIi'lli LSaimnrl Gizossirxx, a citizen of the United States, and resident of the city of New York, borough of the Bronx, in the county of Bronx and State of New York, have invented a new and Improved Building Element, of which the following is a full, clear, and exact description.

This invention relates to fireproof building constructions and has particular reference to the construction of stair treads or other building units.

Among the objects of the invention is to provide a substantially flat building unitadapted for stair treads, and comprising a base or shell made of relatively thin metal but so formed as to possess maximum strength, said shell being provided with a body or filler of any suitable material.

Another object of the invention is to provide a stair element or step providing not only for maximum stiffness and strength and minimum weight but also to provide for maximum light and air as well as cleanliness.

With the foregoing and other objects in view the invention consists in the arrangement and combination of parts hereinafter described and claimed, and while the invention is not restricted to the exact details of construction disclosed or suggested herein, still for the purpose of illustrating a practical embodiment thereof reference is had to the accompanying drawings, in which like reference characters designate the same parts in the several views, and in which- Figure 1 is a perspective view of a series of steps, the treads of which are in accord ance with one form of my invention.

Fig. 2 is a perspective view of one of the shell or base members detached, in the form adapted for a short tread.

Fig. 3 is a vertical transverse sectional detail on the line 33 of Fig. 1: and

rig. 4 is a vertical longitudinal section on the line 4-4: of Fig. 3.

Referring now more particularly to the drawings adaptation of my improvement for stair construction in which there are shown a series of treads 10 connected at their ends to stringers 11. Each tread comprises a sheet metal base 12 preferably made of uniform thickness and of a length to fit snugly against the inner or opposed vertical walls of the stringers. Each base 12 is provided inwardly projecting I show in Fig. 1 that practicalalong its two side edges with upwardly and flanges 13 of any suitable heig'ht or design for several purposes: first, to provide a rounded finish for the exposed edges of the tread; secondly, to provide strength and rigidity for this part of the tread, and thirdly, to provide means to lock and hold in place a body or bed 1 1 of asphalt, concrete or other suitable filling material.

In addition to the' edge flanges 13 I provide one or more, any suitable number, of longitudinal downward crimps15 parallel to said edges. The number of these crimps will depend upon the span or length of the tread, the gage of the metal, and any special provisions of the building specifications. In addition to the provision of strength afforded by these crimps, they serve to assist in holding the body 1 1 in place, by reason of the fact of strips or tongues of the filler projecting into the V-shaped valleys formed by the crimps.

lVhil'e the ends of the base 12 are cut substantially square with respect to the gen eral direction of the tread I provide a recess 16 in each end to accommodate the angle bracket 17 which has its vertical flange fitted into said recess 16 while the upper or horizontal flange of the bracket may lie flatly against the inner surface of the base 12. In the construction of stair treads which are made up in standard sizes and erected as independent building elements the supporting brackets 17 are secured in the position indicated not only by rivets 18 but also by the body of the filler 1 In the finished structure therefore the only part of the bracket that is visible is a portion of the vertical flange thereof, that portion that projects below the base 12 and is secured by rivets or their equivalent fasteners 19 to the stringers. Fig. 2 indicates the appearance of the base member 12 constructed for a short tread having a single crimp between the edge flanges 18.

From what has been set forth above it will be understood that I provide a construction which is not only rigid, strong and easily assembled, but one which is of the most sanitary nature because of the fact that the space between adjacent treads is free and unobstructed and because there are no corners, angles or other irregular forms of construction where dust, filth or the like, can accumulate.

I claim:

A tread for stairs, comprising a base formed of a rectangular sheet metal plate having at each longitudinal edge an upwardly projecting flange, the flanges being of the same height and each bent inwardly to form a rounded edge, the base between the flanges being crimped downwardly forming V-shape valleys, extending longitudinally throughout the length of the base, the portions between the valleys and the valleys and flanges being flat, the base being provided at its ends with downwardly extending right angular securing flanges, and a filler or tread proper of plastic material on the base and held thereon by the flanges and valleys.

SAMUEL GROSSMAN.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of ratentl.

Washington, D. G." 

